1. Field of the Invention
The invention relates to semiconductor components and somewhat more particularly to a method of producing semiconductor components, such as transistors, diodes, Schottky diodes, resistors in integrated circuits, etc.
2. Prior Art
In the production of integrated circuits, particularly LSI (large scale integration) circuits, a constant desire is to achieve as high a structural packing density as possible while maintaining the production procedure as simple as possible in order to increase the manufacturing yield. Heretofore, suggestions have been made to dispense with buried layers and epitaxial layers which are typically provided on semiconductor substrates, so as to achieve a greater packing density. Since adjacent semiconductor components or elements in an integrated circuit must be electrically insulated from one another in order to prevent one component from undesirably interfering with another, so-called "tubs" are provided around each component in the foregoing process. These tubs are typically produced by implantation or diffusion techniques, preferably with a n-conductive dopant into a p-conductive semiconductor substrate.
However, due to the absence of, for example, a diffusion-produced buried layer with the foregoing process, a high collector path impedance as well as a high collector substrate capacitance occur, the undesirable influence of which is further increased by a substantial collector base capacitance because of the absence of an epitaxial layer. Further, tubs require a specific amount of space and this prevents attainment of maximum component packing density. Yet further, adjustment of individual masking steps during this process presents problems because no self-adjusting alignment procedure appears possible.